Abstract. This article discusses protostellar disk dispersal due to photoevaporation by ultraviolet and X-ray photons from the central star. The current theoretical understanding of disk dispersal is summarised and observational constraints are discussed. Disk lifetimes due to photoevaporation are typically ∼ a few million years and depend on stellar mass, radiation field, disk viscosity, and dust evolution.

Key words:stars: formation -- protoplanetary disks; accretion: accretion disks